Bioequivalence and Bioavailability Forum

Dear Helmut,
Dear all!

Happy New Year!

I have a question about the strength to be selected in a bioequivalence study for FDA.

We have 4 different strengths for a BCS class II product: 50 mg; 100 mg; 200 mg and 400 mg.
Analyzing the reference formulation, we found that we have proportionality in composition between the 200 and 400 mg, but not between 50, 100 and 200 mg. The difference in composition for inactive ingredient (most possible lactose) is over 10% for these strengths.
The FDA guidance (draft) recommends bioequivalence only for 400 mg, and
Waiver request for 100 mg and 200 mg based on …proportionally similar across all strengths.
We don’t have any information about 50 mg strength.

In this case, is it needed to perform bioequivalence for 50 mg, 100 mg and 400 mg?

Thank you for help.
Regards
Ioanam